Shock-absorbing apparatus for drilling machines using wire cables



Aug. 2o, 1929.

SHOCK ABSORBING APPARATUS FOR DRILLING MACHINES USING WIRE CABLES F. F.DAvls v 1,724,913

Aug. 20, 1929. F. F, DAvls 1,724,913

SHOCK ABSORBING APPARATUS FOR DRILLING MACHINES USING WIRE CABLES FiledMay 6, 1926 2 Shets-Sheet 2 111; 4 116 g 5 ai: l f 2gb l" 5 /0 Fig. v 4K'l 4Z lNvENToR FranciSFa/colzerawl ATTORNEY 'l Mig@ Patented Aug. 20,1929.

UNITED STATES PATENT OFFICE.

FRANCIS FALCONER DAVIS, OF MONTEREY, CALIFORNIA, ASSIGNOR TO FRANCISHARLEY DAVIS, OF MONTEREY, CALIFORNIA.

SHOCK-ABSORBING APPARATUS FOR DRILLING MACHINES USING WIRE CABLES.

App1icatio. filed May 6, 1926.

The present invention is an improvement of the devices disclosed in myco-pending applications, eSrial Nos. 756,936 and 80,956 and relatesbroadly to cable drilling machinery, but refers more particularly toportable drilling rigs used for vspudding-in shallow water wells, quarryblast holes, and the like; such rigs as customarily have a derrick ormast provided with a crown sheave at or near the top thereof for thesupport and service of the tool-carrying sable.

Specifically my device may be classed as what, in driller parlance isknown as, a cracker several forms of which are known to the prior art,but in relation to which my present device is a novelty and a decidedimprovement.

A cracker device is for use when drilling with the nonelastic steel wirecable instead of the elastic fiber cable so largely in present use. Acracker' consists of a liber cordage member interposed at some pointbetween the drilling tool and the spudding beam so as to deaden theshock that attends drilling when steel wire cable is used as the toolcarrier.

One, and probably the most successful form of cracker in present use inthe art consistsv of a length of manila cable or hawser, about onehundred feet long, whose lower end is attached to the rope-socket of thedrilling tools and the upper end thereof is attached to the lower end ofthe wire cable.

lith a cracker of this length (which however is obviously inadmissiblein shallow holes) a satisfactory simulation of a. cordage-carried drillcan be secured even though the remainder of the cable leading from thetop of the cracker to the winding drum be non-elastic.

There are also various forms of derrick mounted crackers which operatewith more or less measure of success. By the use of the present crackera perfect simulation of the drilling action of an elastic cordagecarrieddrill can be attained while wire-line drilling, with the added advantageof being able to drill with a rapid drilling motion irrespective of thedepth of the hole, of the weight of the drill employed, or as to whetheror not the drilling is being done in a wet hole or a dry one.

The increasing demand for shallow drillings makes the use `of wirecablein lieu of Serial No. 107,197.

the liber cable so largely in present use a matter of seriousimportance, wire being less expensive than ber cordage, longer-livedunder the severe stresses which accompany drilling by the s puddingprocess.

An object of this invention is to provide a drilling-machine derrick, ormast structure, with an improved method of housing a movablecrown-sheave bearing.

A further object is to provide an elastic member, or cracker, for thesupport of the crown-sheave bearing, said elastic cracker being adaptedto receive tensional adjustments from above.

Another' object is to provide a drill-supporting structure with alifting means adapted to apply strain to a cracker member in an upwarddirection.

An additional object is to provide a girthlike cracker adapted to betensed by upward strain applied at a point of the derrick structure thatis higher than the level of the bight of the said girth.

Another object is to provide a winding means adjacent the top of aderrick structure, the said means being adapted for applying regulativeup and down adjustment to an elastic girth-likeelement.

Another object is to provide a rigid spacing means adapted' to ride onthe bight of the elastic cracker element for the support of acrown-sheave bearing in a buoyantvmanner as regards the longitudinalaxis of the said derrick structure.

A further object is to provide asan article of manufacture, acrown-sheave block adapted to it the top of a derrick structure; withinthe said block a piston-like crownsheave bearing adapted for limited upand down movement, said block embodying a winding means adapted to applystrain to an elastic cracker member.

Another `object is to provide a crownblock structure with a taperedYsocket adapted to fit a mast or derrick top and to slip downwardly overthe said top so as to compensate for shrinkage.

A further: object is to provide a structure of great eiciency and onethat is not liable to get out of order.

Another object is to provide an anuXiliary cushioning means to aid theelastic element aforesaid at the end of the down stroke;

Other objects and advantages will appear during the course of thefollowing description.

. In the accompanying drawings forming a part of this specification, andin which like numerals are employed` to designate like parts throughoutthe same,-

Figure 1 shows a side elevational view ot a drilling machine mastequipped with my apparatus.

Figure 2 is a rear elevation al view of the apparatus.

Figure 3 is a cross-section taken on the line ll-vll of Figure 2.

Figure il is a genera-l side View of a drilling machine embodying myapparatus.

Referring now in close detail to the drawings: Figure l shows thenon-elastic drilling cable 6 leading from the hoisting drum 7 round thecontacting circumferential portions of the sheave, thence passing underthe sheaves fL and S and over the crownsheave 9 and on to therope-socket 115 at the head of the drilling tool.

As best shown in Figure 2, it will be seen f that the crown-sheave 9 iscarried by the shaft 11b in the crown-sheave bearing 11, the saidshea-ve 9 being adapted for revoluble movement either with the shaft 11bor as a loose member on the said shaft, there being a transverseperforation 11e suitably7 disposed in the wall of the crown-blockstructure 10 Jfor the purpose of inserting said shaft in said bearingfor the revoluble support of the said crown-sheave.

The bearing 11 is adapted to slide up and down for a predetermineddistance within the internal space 11a of the crown-block structure 10,the said bearing being provided with the suitablycored recess 43 andwith the downwardly-projeciing shank 12, the said snank being adaptedfor 'fastening ot the bearing 11 to the rigid spacing-means 17, whichmeans may well be either a shaft of suitable sir/.e and shape or a pipe.The shank 12 as shown in Figure 2 carries the cushion-spring 13 which isretained in place bythe keeper lila, an annular ring, the said keeperbeing prevented from falling oil the shank 12 by the keeper-pin 1l. Thebearing 11 is inserted from the top of the struc-A ture 10 by irstremoving the cover 36.

As shown, the pin 14- serves to secure the spacing means 17 to the shank12, the said shank being bored out to receive the upper end ,ot the saidmeans 17.

A suitable distance belowT the end of shank 12 is the abutment 15preferably formed integral with the body of the crown-block. structure10, said abutment being provided with a vertical perforation orabutment-hole 16, said hole being of sufficiently large diameter 'forthe shank 12 with the slightly-projecting keeper-pin 14 to play in andout of, although suiliciently restricted in diameter to form an abutmentfor the keeper 14a to abut against when t-he drill is being lifted.

The interior portion of structure 10 from the under side of the abutment15 down to the lower end 22a is conformed to lit over the head of themast 23 which is tapered on all four sides and lett a trifle large toallow for shrinkage of the timber, consequently there is a space as 22bleft between the under side of the abutment 15 which is designated 22and the upper end of the mast 23. New, as thesaid space would graduallydiminish in height due to the downward travel ot the structure 10 on thetaper et the mast 23, when effected by the shrinkage of the said nast,the recess 38 is provided in the top o1" the said mast for theaccommodation of the shank 12.

The mast 23, as best shown in Figure 1, is of composite structure, thelower portion thereof being composed or" the channels 24-2-1 whichextend upwardly 'for a considerable distance from the ground, the saidchannels being secured by bolts as 112 to the lower portion of a timberof suitable length to give the required height to; the derrickstructure, and, for the purpose of illus ation, say twelve inchesrbytwelve inches in cross-section; a suitable taper being given to theupper end thereoi1 as' described so that the ycrown-block structure 10which is preterably a steel casting may be slipped over the top ,of thesaid mast and wedge itself thereon without need of other attachment, asall the tendency of the drilling operations is to drive the structurefarther and more firmly over the mast head. lt is obvious, however, thatsuch a crown-block structure 10 could be adapted for use on derricks ofdifferent construction from that above mentioned, it could be used witha derric.; composed entirely of structural steel elements, or one madeof pipe, without deparing from the spirit of the invention.

The spacing means 17 passes down through the abutment-hole 1G and downthrough the central axis of the member 23, (which is bored to receiveit) until the lower end of the said means projects a suitable llOdistance below the lower end of the mem- Y ber 23 at the point 39 forthe attachment of the pressure-toot 18 to the said lower end orP means17, which attachment may be obtained by the insertion of the end ofmeans 17 into a socket as 2O and secured therein by suitable means,removable or not.

The pressure-foot 18, as best shown in Figure 2 is located between thetwo channels 2l-24= and stands upon the bight of the elastic girth-likemember 19 the parts of which 19a and 191 are seen'to extend upwardly oneone each side or the mast structure 23. The said parts being adapted tobe pulled evenly in an upwarddirection by winding means pawls 32-32, thesaid ratchets in the to which the said parts may either be attacheddirect or be attached by means of the rope socket 27 27 and wire ropeextension as 28-28, or by other suitable means.

As best shown in Figure 2, the parts 19a and 19h of the elasticgirth-like member 19 are pieced out by the flexible wire rope 28-28 theends of which are secured to the drum 29-29 the said drums being securedto the shaft 30 which is rotatable in the bearings 3LP-34 and adapted toexert upward strain upon the member 19 when leverage is applied to thehandle 31 in a counter clock-wise direction, and a consequent flexing ofthe said member with a clock-wise movement of the said handle 31, bothmovements being under the regulative control of the ratchets 323-33 inco-action with the present instance being' formed integral with the drum29-29, the said pawls being secured appropriately to the flanges 352tand 35h.

The operation of my device is as follows Assuming that the string ofdrilling tools is suspended over the crown-sheave 9 by the non-elastictool carrying wire cable 6 whose slack has been taken up on thehoistingdrum 7 and held in check by brake means not shown as it forms nopart of the present invention. In this position the lower surface of theannular keeper 14a rests in contact with the upper surface of theabutment 15 so that such weight as is present is borne by thecushion-spring 13.

Assuming now that counter clock-wise movement has been imparted to thehandle 31, and that the drums 29-29 have been rotated so as to take upthe slack and apply a lifting influence to the extension ropes 28-2S,thereby causing a direct upward pull upon the elastic girth-like member19; assuming further that an upward pull of sufficient degree has beenapplied to the said member so as to elevate the crown-sheave 9 until itreaches a. level approximately half way up the mouth 37 of thecrown-block structure 10,-as best shown in Figure 2,- and, thatregulated adjustment of the parts involved is maintained by theco-action of the pawls 32-32 with the ratchets 33-33 until the drillingtools are lifted clear off the bottom of the drill-hole and are carriedon the said girth-like member 19 in a buoyant manner, similar to that ofa child seated in that well known device called A babybouncer.

Vhen the drill is in action, as each downward stroke of the bearing 11nears its downward limit, just when the strain on the girthlike element19 is becoming the most severe and tends to fatigue the fibers of thesaid girth 19, the cushion-spring 13 comes into play in conjunction withthe abutment 15 and relieves the excessive strain that otherwise wouldhave to be borne by the member 19 alone.

To perform the kdrilling act a suitable agent transmits power from thedrum-shaft 2 to the spudding beam 3 through the crank 4 and pitman 5thereby causing the beam 3 to oscillate in an up and down manner; thus,by alternately depressing and releasing the non-elastic sable 6 thedrill is caused to reciprocate. Said cable 6 being nicely fed out fromthe hoisting drum 7 as the hole deepens; the weight of the drillmeanwhile being borne in a shockless manner on the elastic girth-likemember 19 in co-operation with the cushion-spring member 13 asexplained.

It is to be understood that the form of my invention, herewith shown anddescribed is to be taken as a preferred example of the same, and thatvarious changes in the shape size and arrangement of parts may beresorted to without departing from the spirit of the invention, or thescope of the subjoined claims.

I claim 1. In an apparatus of the kind described, an elastic girth-likeelement depending fromv a mast or derrick structure, a crown-sheaveadapted for rotary and up and down movement, the crown-sheave supportedon the said element. by a spacing means, and regulative means fortensing or flexingv the said element from above, substantially asdescribed and for the purposes set forth.

2. A shock-absorbing apparatus adapted for use as a crown block for adrilling-machine using Wire drilling cable, said apparatus comprising incombination, a structure adapted ixedly to surmount a derrick-likesupporting body, said block being provided with a revoluble sheavemounted in a bearing adapted for up and down movement, elongated slotsin said block being disposed at right angles to the axis of said sheaveand of sufficient lengt-h and apt location to accommodate the up anddown play of said sheave, an elastic element on the. structure, spacingmeans eo-acting with said bearing and with the elastic element for theresilient support of said sheave, together with regulatively-adjustablemeans carried, by said block for tensing or relaxing said elasticelement so as to adjust the height of said sheave relative to the saidslots when carrying tools of different weights.

3. In a shock-absorbing crown block for a drilling machine having meansfor attachment to a derrick structure, a revoluble crown sheave mountedin a bearing adapted for up and down movement within said block, anelastic girth-like element depending from said block, a spacing meansengaging said girth for the resilient support of said bearing,regulative means for tensing and flexing said element from above and aspring means independently carried by said fil bearing and adapted toContact at the ends of each down-stroke of said bearing with anabutment, said Contact thereby compressing said spring and providingcushioned relief for said element when under severeSt strain.

4. In an apparatus as specified in claim 1, said Crown sheave beingsuitably mounted in an elongated, tapering, shell-likevstructure adaptedto lit on to the free upper end of a 10 mast or derrick.

5. In an apparatus as set forth in claim 1,

and in combination; said sheave suitably,

mounted in an elongated, tape-ring structure, the lower end of saidstructure making tapering connection with the top of a mast or derriek,and said regula/tive means carried by the structure.

In testimony that I claim the above as my own I have hereunto subscribedmy name this 24th day of April, 1926.

e FRANCIS FALCONER DAVIS.

CERTIFICATE OF CORRECTION.

Patent No. 1,724,913. Granted August 20, 1929, to

FRANCIS FALCONER DAVIS.

It is Iiereby certified that errer appears in the printed specificationof the above nmnlsered patent requiring cerrectienas follows: Page l,line 2, for "copending" read copending"; line 3, for the misspelled word"eSrial"-read "Serial"; line 11, for "sable" read "cable"; line 106, forthe misspelled word "anuxiliary" read "anxiliary"; page 3, lines 9 and21, for drum" read "drun1s"; and line 74, for "sable" read "cable"; andthat the said Letters Patent should be read With these eorrectienstherein that the same may conform to the record of the case in thePatent Office.

Signed and sealed this 15th day of October, A. D. 1929.

t: M. J. Moore,

(Seal) Acting Commissioner of Patents.

